Standard dynamic range (SDR) media, including images, videos, and renderings, has a limited dynamic range for luminance values or brightness of pixels, constrained by the bit depth or number of bits that may be used to represent the luminance of the pixels according to encoding and decoding standards (e.g. 8 bits per sample). By contrast, high dynamic range (HDR) media standards provide more bits or a greater bit depth (e.g. 12, 16, 24, 32 bits or more per sample), allowing a greater range in the image between white and black or bright and dark regions without introducing unacceptable amounts of contouring due to excessive quantization. As a result, media may have higher contrast, darker dark sections and brighter bright sections.
Converting between SDR and HDR or between different HDR media formats may be difficult due to non-linear relationships between values in the SDR format luminance range and values in the HDR format luminance range or between different HDR format luminance values. Similarly, it may be difficult to convert between different HDR formats (e.g. HDR formats with different bit depths or color spaces or different perceptual luminance quantizers). In particular, many implementations of SDR/HDR or HDR/HDR format conversions result in substantial chroma hue shift that may be quite noticeable to the viewer.
The details of various embodiments of the methods and systems are set forth in the accompanying drawings and the description below.